<template>
  <div class="two">
    {{ value }}
    <button @click="$emit('input', value + 1)">累加</button>
  </div>
</template>

<script>
export default {
  name: 'Two',
  props: ['value'],
};
</script>

<style scoped>
.two {
  border: 1px solid red;
}
</style>
